Try to create a prism dialog service with custom modern ui window

App/App.xaml.cs

@@ -1,4 +1,5 @@
 using System.Windows;
+using Dialogs;
 using ModernWpf;
 using ModernWpfPlayground.Types;
 using Prism.Ioc;
@@ -22,6 +23,7 @@ namespace ModernWpfPlayground
         {
             containerRegistry.Register<MainWindow>();
             containerRegistry.Register<MainWindowViewModel>();
+            containerRegistry.RegisterDialog<MessageBoxView, MessageBoxViewModel>();
         }
 
         protected override Window CreateShell()

App/MainWindow.xaml

@@ -242,6 +242,7 @@
                                         HorizontalAlignment="Stretch"
                                         Command="{Binding SaveViewModelCommand}"
                                         Content="Save" />
+                                    <Button Command="{Binding ShowDialogServiceCommand}" Content="Show dialog" />
                                 </ui:SimpleStackPanel>
                             </Grid>
                         </ScrollViewer>
@@ -275,7 +276,8 @@
                                         x:Name="TextBoxSwitch"
                                         Grid.Column="0"
                                         Width="145"
-                                        Margin="0,0,5,0">
+                                        Margin="0,0,5,0"
+                                        VerticalAlignment="Top">
                                         <ToggleButton.Style>
                                             <Style BasedOn="{StaticResource {x:Type ToggleButton}}" TargetType="ToggleButton">
                                                 <Setter Property="Content" Value="Read/Write" />
@@ -289,8 +291,12 @@
                                     </ToggleButton>
                                     <TextBox
                                         Grid.Column="1"
+                                        AcceptsReturn="True"
+                                        AcceptsTab="True"
                                         IsReadOnly="{Binding IsChecked, ElementName=TextBoxSwitch}"
-                                        Text="Eine einfache Textbox" />
+                                        MinLines="4"
+                                        Text="{Binding MultiLineText}"
+                                        TextWrapping="Wrap" />
                                 </Grid>
                                 <controls:PropertyPresenter Label="Hello" Value="{Binding BooleanValue}" />
                                 <controls:PropertyPresenter Label="Hello">

App/MainWindowViewModel.cs

@@ -3,10 +3,12 @@ using System.IO;
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Input;
+using Dialogs;
 using Microsoft.Win32;
 using ModernWpfPlayground.MvvmStuff;
 using ModernWpfPlayground.Types;
 using Prism.Commands;
+using Prism.Services.Dialogs;
 using YamlDotNet.Serialization;
 using static ModernWpf.ThemeManager;
 
@@ -15,14 +17,16 @@ namespace ModernWpfPlayground
     // ReSharper disable once ClassNeverInstantiated.Global
     public class MainWindowViewModel : BaseViewModel
     {
+        private readonly IDialogService _service;
         private const string AppName = "TaBEA 3.0.0";
         private string? _path;
         private string _title = AppName;
         private readonly ISerializer _serializer;
         private readonly IDeserializer _deserializer;
 
-        public MainWindowViewModel()
+        public MainWindowViewModel(IDialogService service)
         {
+            _service = service;
             ShowDialogCommand = new DelegateCommand(ShowDialog);
             CloseCommand = new DelegateCommand(() => Application.Current.Shutdown());
             OpenViewModelCommand = new DelegateCommand(LoadViewModel);
@@ -121,6 +125,25 @@ namespace ModernWpfPlayground
             set => SetProperty(value);
         }
 
+        public string MultiLineText
+        {
+            get => GetProperty("Multi line");
+            set => SetProperty(value);
+        }
+
+        public ICommand ShowDialogServiceCommand => new DelegateCommand(ShowDialogService);
+
+        private void ShowDialogService()
+        {
+            void executeCallBack(IDialogResult result)
+            {
+
+            }
+
+            _service.Show(nameof(MessageBoxView), default, executeCallBack);
+
+        }
+
         private static void SetTheme(ThemeMode themeMode) => Current.ApplicationTheme = themeMode.ToApplicationTheme();
 
         private void ShowDialog()

App/ModernWpfPlayground.csproj

@@ -9,7 +9,7 @@
 
   <ItemGroup>
     <PackageReference Include="FastMember" Version="1.5.0" />
-    <PackageReference Include="ModernWpfUI" Version="0.9.0" />
+    <PackageReference Include="ModernWpfUI" Version="0.9.1" />
     <PackageReference Include="Prism.DryIoc" Version="8.0.0.1740-pre" />
     <PackageReference Include="Prism.Wpf" Version="8.0.0.1740-pre" />
     <PackageReference Include="YamlDotNet" Version="8.1.2" />
@@ -19,6 +19,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\Controls\Controls.csproj" />
+    <ProjectReference Include="..\Dialogs\Dialogs.csproj" />
   </ItemGroup>
 
 </Project>

App/Types/AccentColors.cs

@@ -18,9 +18,9 @@ namespace ModernWpfPlayground.Types
         {
             return accentColor switch
             {
-                AccentColors.Green => Color.FromRgb(0, 86, 76),
+                AccentColors.Green => Color.FromRgb(33, 115, 70),
                 AccentColors.Yellow => Color.FromRgb(164, 144, 0),
-                AccentColors.Blue => Color.FromRgb(0, 120, 215),
+                AccentColors.Blue => Color.FromRgb(43, 87, 154),
                 AccentColors.Purple => Color.FromRgb(104, 33, 122),
                 AccentColors.Red => Color.FromRgb(183, 71, 42),
                 _ => throw new ArgumentOutOfRangeException(nameof(accentColor), accentColor, null)

Controls/Controls.csproj

@@ -7,7 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="ModernWpfUI" Version="0.9.0" />
+    <PackageReference Include="ModernWpfUI" Version="0.9.1" />
     <PackageReference Include="System.Drawing.Common" Version="4.7.0" />
   </ItemGroup>
 

Dialogs/AssemblyInfo.cs

@@ -0,0 +1,10 @@
+using System.Windows;
+
+[assembly: ThemeInfo(
+    ResourceDictionaryLocation.None, //where theme specific resource dictionaries are located
+                                     //(used if a resource is not found in the page,
+                                     // or application resource dictionaries)
+    ResourceDictionaryLocation.SourceAssembly //where the generic resource dictionary is located
+                                              //(used if a resource is not found in the page,
+                                              // app, or any theme specific resource dictionaries)
+)]

Dialogs/DialogService.cs

@@ -0,0 +1,32 @@
+//using System;
+//using Prism.Services.Dialogs;
+
+//namespace Dialogs
+//{
+//    public class DialogService : IDialogService
+//    {
+//        /// <inheritdoc />
+//        public void Show(string name, IDialogParameters parameters, Action<IDialogResult> callback)
+//        {
+//            TODO_IMPLEMENT_ME();
+//        }
+
+//        /// <inheritdoc />
+//        public void Show(string name, IDialogParameters parameters, Action<IDialogResult> callback, string windowName)
+//        {
+//            TODO_IMPLEMENT_ME();
+//        }
+
+//        /// <inheritdoc />
+//        public void ShowDialog(string name, IDialogParameters parameters, Action<IDialogResult> callback)
+//        {
+//            TODO_IMPLEMENT_ME();
+//        }
+
+//        /// <inheritdoc />
+//        public void ShowDialog(string name, IDialogParameters parameters, Action<IDialogResult> callback, string windowName)
+//        {
+//            TODO_IMPLEMENT_ME();
+//        }
+//    }
+//}

Dialogs/Dialogs.csproj

@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <UseWPF>true</UseWPF>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Prism.Wpf" Version="8.0.0.1740-pre" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Reference Include="ModernWpf.Controls">
+      <HintPath>..\..\..\.nuget\packages\modernwpfui\0.9.1\lib\netcoreapp3.0\ModernWpf.Controls.dll</HintPath>
+    </Reference>
+  </ItemGroup>
+
+</Project>

Dialogs/MessageBoxView.xaml

@@ -0,0 +1,27 @@
+<ui:ContentDialog
+    x:Class="Dialogs.MessageBoxView"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:local="clr-namespace:Dialogs"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    xmlns:mvvm="http://prismlibrary.com/"
+    xmlns:ui="http://schemas.modernwpf.com/2019"
+    Title="Save your work?"
+    d:DataContext="{d:DesignInstance local:MessageBoxViewModel}"
+    d:DesignHeight="450"
+    d:DesignWidth="800"
+    mvvm:ViewModelLocator.AutoWireViewModel="True"
+    CloseButtonText="Cancel"
+    DefaultButton="Primary"
+    PrimaryButtonCommand="{Binding CloseDialogCommand}"
+    PrimaryButtonCommandParameter="true"
+    PrimaryButtonText="Save"
+    SecondaryButtonText="Don't Save"
+    mc:Ignorable="d">
+    <StackPanel HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
+        <!--  Content body  -->
+        <TextBlock Text="Lorem ipsum dolor sit amet, adipisicing elit." TextWrapping="Wrap" />
+        <CheckBox Content="Upload your content to the cloud." />
+    </StackPanel>
+</ui:ContentDialog>

Dialogs/MessageBoxView.xaml.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+namespace Dialogs
+{
+    /// <summary>
+    /// Interaktionslogik für MessageBoxView.xaml
+    /// </summary>
+    public partial class MessageBoxView
+    {
+        public MessageBoxView()
+        {
+            InitializeComponent();
+         }
+    }
+}

Dialogs/MessageBoxViewModel.cs

@@ -0,0 +1,50 @@
+using System;
+using Prism.Commands;
+using Prism.Services.Dialogs;
+
+namespace Dialogs
+{
+    public class MessageBoxViewModel : IDialogAware
+    {
+        /// <inheritdoc />
+        public bool CanCloseDialog()
+        {
+            return true;
+        }
+
+        /// <inheritdoc />
+        public void OnDialogClosed()
+        {
+            
+        }
+
+        /// <inheritdoc />
+        public void OnDialogOpened(IDialogParameters parameters)
+        {
+        }
+
+        /// <inheritdoc />
+        public string Title { get; }
+
+
+        private DelegateCommand<string> _closeDialogCommand;
+        public DelegateCommand<string> CloseDialogCommand => _closeDialogCommand ??= new DelegateCommand<string>(CloseDialog);
+
+        private void CloseDialog(string obj)
+        {
+            if (obj == "true")
+            {
+                RaiseRequestClose(new DialogResult(ButtonResult.OK));
+            }
+
+        }
+
+        /// <inheritdoc />
+        public event Action<IDialogResult> RequestClose;
+
+        public virtual void RaiseRequestClose(IDialogResult dialogResult)
+        {
+            RequestClose?.Invoke(dialogResult);
+        }
+    }
+}

ModernWpfPlayground.sln

@@ -7,6 +7,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ModernWpfPlayground", "App\
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Controls", "Controls\Controls.csproj", "{3884FD41-5A46-4A67-A147-57C36F0059DC}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Dialogs", "Dialogs\Dialogs.csproj", "{56468B07-B709-43E9-8FB9-54EDD5219D69}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -21,6 +23,10 @@ Global
 		{3884FD41-5A46-4A67-A147-57C36F0059DC}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{3884FD41-5A46-4A67-A147-57C36F0059DC}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{3884FD41-5A46-4A67-A147-57C36F0059DC}.Release|Any CPU.Build.0 = Release|Any CPU
+		{56468B07-B709-43E9-8FB9-54EDD5219D69}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{56468B07-B709-43E9-8FB9-54EDD5219D69}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{56468B07-B709-43E9-8FB9-54EDD5219D69}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{56468B07-B709-43E9-8FB9-54EDD5219D69}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE